Merge remote-tracking branch 'origin/master'

license/src/main/java/iot/sixiang/license/service/impl/DeviceServiceImpl.java

@@ -119,7 +119,9 @@ public class DeviceServiceImpl extends ServiceImpl<DeviceMapper, Device> impleme
         queryWrapper.eq(Device::getSnBind, snBind).last("limit 1");
         Device device = deviceMapper.selectOne(queryWrapper);
         if (device != null) {
-            device.setSn(CommonUtil.genRandomNum(18));
+            if (snBind.equals(device.getSn())) {
+                device.setSn(null);
+            }
             device.setSnBind(null);
             device.setStatus(0);
             device.setUpdateTime(new Date());